Semiconductor devices are used for many applications, and one component used extensively in semiconductor devices is a transistor. There are many different types of transistors, including bipolar junction transistors. Bipolar junction transistors (“BJTs”) are used to make other types of transistors and devices, such as a complementary metal oxide semiconductor (“CMOS”), which utilizes NPN and PNP BJTs for increased performance.
Many processes are used in manufacturing BJTs. One such process is annealing. One function of annealing is to control the formation and diffusion of various dopants. A problem with annealing is that too much, or too little, diffusion of dopants occurs depending on the time and temperature of the annealing process. Depending on the type of BJT being manufactured, an annealing process can cause undesirable base concentrations and base widths as well as undesirable emitter widths. Accordingly, these undesirable attributes can hurt BJT performance, including reduced speed, band-to-band tunneling, and less than optimal linearity. Therefore, semiconductor manufacturers desire methods of manufacturing BJTs that control the formation and diffusion of dopants so that the performance of BJTs is improved.